Electrical heating means



Jan. 4, 1938. H. GEORGE ET AL I 2,104,557

I ELECTRICAL HEATING MEANS Original Filed Jan. 27, 1954 2 Sheets-Sheet l2 u /95 v l 96 77 7T9 i- ATTORNEYS Patented Jan. 4, 1938 UNITED STATESPATENT OFFICE Paris, France Original application January 27, 1934;Serial No. 708,618. Divided and this application May 16, 1936, SerialNo. 80,052. In France January This invention relates to heating means,and relates more particularly to electrical furnaces for heating, fusingand/or casting articles made of substances having a high melting point.

The present application is a division of our copending patentapplication relating to Heating means, Serial No. 708,618, filed January27, 1934, and is particularly concerned with the type of furnaces usedfor liquid fusion.

In our copending patent application relating to Electrical heating,Serial No. 648,996, filed December 27, 1932, an electrical furnace isdescribed which comprises a heating element consisting of a carbon rodand surrounded by a container which is situated within the zone of heatradiated by the heating element and whichis movable with respect to thiselement. A gaseous medium may be introduced into the furnace and allowedto flow between the heating element and the walls of the container.

'An object of the present invention is to provide certain improvementsin furnaces of this type to increase their output and their efliciency.

In order to increase the output of the furnaces it is necessary to havethe successive operations of melting in said furnaces following eachother within a time as short as possible and in order to increase theefficiency of the furnaces. The losses of heat between two successiveoperations must be reduced as much as possible.

Consequently an object of the present invention is to facilitate theinsertion of the heating element into a rotatable furnace and theremoval of the heating rod therefrom and to shorten as much as possiblethe time necessary for these operations.

The heating element may comprise a single heating rod or several rodswhen a polyphase current is to be used.

The insertion and the removal of the heating element are rendered easyby connecting one of its ends to a movable organ of the furnace.

The other end of the heating element may be supported by another organand in this case, resilient means are used to press said organ againstthe end of the heating element in order to maintain a steady contactbetween the terminals and the heating element at both ends of saidelement, in spite of the movements or expansion of the-various parts ofthe furnace in the course of the heating or fusing process.

Another object of the invention is to provide for an air-tightconnection between the terminals and the rotatable parts of the furnace,when it is necessary to have the fusing zones of furnaces devoid ofcontact with the surrounding atmosphere, the furnace being given anoscillating motion instead of a rotating one.

The above and other objects of the present invention may be realizedthrough the provision 3 Claims. (01. 13-21) of an electrical furnace orfurnaces which comprise a heating .rod having one end which is firmlyconnected to a block which may consist of one or several elements. Theblock is supported in such manner that the height at which the heatingrod is maintained may be conveniently adjusted. The block is preferablymounted upon a carriage which is movable in a direction parallel to theaxis of the container which encloses the heating rod and which carriesthe material to be treated. If the heating rod has a small or mediumsized diameter, it is advisable to provide screw threads upon one end ofthe heating rod and to screw that end into the supporting block. Theopposite end of the heating rod may lie freely upon a second block whichis located at the opposite end of the container. If the heating elementis to be heated by a polyphase electrical current, it should consist ofseveral rods, equal justed by adjustment of the means supporting theheating element, by adjustment of both the means supporting the heatingelement and the means supporting the container, or solely by adjustmentof the position of the container. The block carrying a heating elementmay be pivotally mounted upon a chariot so that when the heating elementis removed from the furnace the heating element may be moved from ahorizontal. to a vertical position and covered by a protective cover.The terminals connected to a source of electrical energy and supplyingan electrical current to the heating element may be carried by the blockmounted upon a carriage and/or by the block situated opposite thefirst-mentioned block.

If two blocks are used, that block which freely supports thenon-threaded end of the heating rod may be made movable, such movementbeing limited by resilient means. 1

The invention will appear more clearly from the following detaileddescription, when taken in connection with the accompanying drawingsshowing preferred embodiments of the inventive idea.

In the drawings:

Figure 1 shows a furnace having an hermetically closed fusing zone inaxial section and partly in side elevation;

Figure 2 is a section alon Figure 1;

the line 2-2 of Figure 3 is a section along the line 8--8 of Figure 1;

' Figure 4 shows on a larger scale and in vertical axial section a partof the furnace illustrated in ure 1;

Figure 5 is a section along the line 5-5 of Figure 4;

Figure 6 shows another part of the furnace illustrated in Figure 1 on alarger scale and in vertical axial section;

Figure 7 is a section along the line 11 of Figure 6;

Figure 8 is a section along the line 8-8 of Figure 6.

The furnace illustrated in the drawings comprises a heating rod orelectrical resistance I50, the end I5I of which is provided with screwthreads, as shown in Figure 4. The opposite end I 52 of the resistanceIII is conical in shape, as shown in Figure 6.

The end I5I of the resistance III is screwed into a threaded bore hole I58 formed in a support I54, which consists of amorphous carbon (Figure4). The opposite end of the resistance I50 is supported in a cavityformed in a block I55, which is also made of amorphous carbon (Figure 6)A part of the block I54 is slightly conical in shape and is carried by asleeve I55. The block I55 is supported by a similar sleeve I51. Bothsleeves are conductors of electricity. A metallic casing I 58 surroundson three sides the block I58 and carries a metallic terminal I58, whichmay be connected to any suitable source of electrical energy not shownin the drawings.

As shown in Figure 6, a metallic casing I surrounds the sleeve I51 andis connected with one of the ends of an elongated tube I". The tube I8I,which is made of a conducting material carries at its opposite end aplate I52, which is firmly connected with another terminal I58.

A water jacket I84 (Figure 4) surrounds the casing I58 and carries 0pipes I55 and I85, one of which serves as an inlet for the water. Thewater circulates between the casing I55 and the walls of the jacket I84and cools the walls of the casing I58.

A sealing ring I81 made of insulating material is situated between thesleeve I58 and a metallic cover I58.

As shown more clearly in Figure 1 of the drawings, the main container ofthe furnace consists of a cylindrical body I88, which surrounds a layer110 consisting of a. heat insulating material. A lining I'll, which ismade of a refractory material surrounds the resistance I50 and issituated between this resistance and the insulating layer I10. Theconical end cover I58 is rigidly connected with the cylindrical casingI88 by rivets or other suitable means.

A jacket I12 shown in Figure 6 is carried by the metallic casing I80 andis connected with two pipes I13 and I 14, which project into theinterior of the tube I8I and which pass through suitable openings formedin the plate I82. The pipes I13 and I14 are used for the circulation ofa cooling medium such as water, used for cooling the metaliic casingI80.

As shown more clearly in Figure 1, the cylindrical casing I88 is rigidlyconnected with a metallic end cover I15. A hollow casing I15, which ispreferably made of sheet metal surrounds the water jacket I12. Africtional sealing ring I11 (Figures 1 and 6) made of an insulatingmaterial is interposed between the casing I18 and the end cover I15. Thecasing I15 is carried by a support 248 and carries a tubular sleeve orguiding member I18 which is provided with flanges I18, rigidly connectedwith the casing I15.

Due to this arrangement, the resistance I50 and its ends are movable toa certain extent within the casing I88 in the direction of itslongitudinal axis. This axial movement is possible because the tube I5Iis movable with respect to the sleeve I 18.

The jacket I84 connected with the metallic casing I58 is movable alongwith the block I54, the resistance I50, the block I55, the sleeve I51(Figure 6) the casing I50 and the tube "I.

The furnace is provided with resilient means for maintaining the propercontact between the end I52 of the resistance I50 and the block I55.These means comprise a bolt I80, one end of which is rigidly connectedwith the casing I15. The bolt I80 has screw threads I8I and carries awinged nut I82 as well as a washer I88.

A coiled spring I84 surrounds the bolt I80 and is in contact at one ofits ends with the washer I88. The opposite end of the spring pressesagainst the bifurcated end I85 of a lever I85 (Figure 8). The lever I88is carried at its lower end by a hook I81, the opposite end of which isrigidly connected with the casing I18. The middle I88 of the lever I85is somewhat bent and surrounds an insulating rod I88, which is firmlyattached to the tube I8I and which passes through a longitudinal slitI80 formed in the sleeve I18.

As shown in Figure 8, a similar lever I8I is situated at the oppositeside of the sleeve I18 and is carried by a hook I82, which is rigidlyconnected with the casing I15. The bifurcated end I88 of the lever I8Isurrounds a bolt I84, which is also carried by the casing I18. The boltI84 is also provided with a coiled spring, which is not shown in thedrawings.

Due to the provision of the springs I84, the levers I88 and MI maintainthe tube I8I in the position shown in Figure 6. Since the tube "I isconnected with the end I52 of the heating rod I50 by the casing I50, thesleeve I51 and the block I55, the resistance I50 will be alwaysmaintained in close contact with the block I55. Otherwise, slightmovements or contractions of the resistance I58 or the block I55 mightcause an interruption of the electrical current between the resistanceI50 and the block I55.

The cylindrical casing I88 is rigidly connected with two rings I85 andI88, which are in contact with rollers I81, I88, and I88 (Figures 1 and2). The roller I81 is pivotally mounted in a support 200, while theroller I88 is pivotally mounted in a support "I. The roller I88 iscarried by the support 202. The fourth roller and its support are notshown in the drawings. The support 280 is carried by the foundation 208,while the supports 20I and 202 are carried by the foundation 284.

The cylindrical casing I88 is rigidly connected with an annular gear205, which meshes with a pinion 208 rigidly connected with a gear wheel201- and rotatably mounted in the support 288. The gear wheel 201 mesheswith a gear 208, which is driven by a motor 208 resting upon the support2I0., The motor is provided with a switch 2| I, which may be used forreversing at periodic intervals the direction of rotation of the motorand thus reversing the direction of rotation of which surrounds thecasing I58 is carried by a frame 2I2 by means of members 2I3 and 2. Theframe 2 I2 is slidable in the vertical direction in two guide members215 and 2 I6, which are rigidly connected with and supported by acarriage 2I'I.

The frame 2I2 rests upon cams 2! and 2I9, which are keyed upon an axle2211, rotatably mounted in the guides 2I5 and 2IB. A wheel 22I is alsokeyed upon the shaft 220 and is provided with a handle 222, which isused for rotating the cams 2I8 and 2I9. The carriage H6 is mounted onWheels 223 and 224 which are movable along rails 225 and 226.

The cams 2I8 and 2I9 are operated and the carriage 2 I1 is moved alongthe rails 225 and 226, when it is necessary to take the heating elementI50 out of the furnace.

In operation, the terminals I59 and IE3 are connected to a source ofelectrical energy, which is not shown in the drawings. Then a currentwill flow through the terminal I59, the block I54, the resistance I50,the block I55, and tube NH and the terminal I63.

When the motor 299 is started, it will revolve the casing I69 throughthe medium of the gear wheels 2'88, 291, 208, and 205. The switch 2 isused to change the speed of rotation of the casing I69 and to reversethe direction of its rotation.

The material to be treated is first inserted into the furnace eitherthrough one of the axial openings or through a door formed in thecontainer I69 and not shown in the drawings. Then the heating rod I50and the other parts of the furnace are assembled in their properpositions. Then the motor 209 is switched on, causing a rotation of thefurnace. Finally, the electric current is switched on and the heatradiated by the 1 heating rod I50 causes the fusion of the material.After the fusing process has been completed the electrical current isswitched off and the liquid material is removed from the interior of thecontainer I69 through an opening not shown in the drawings.

By the described construction the insertion of the heating elements intothe furnace and the removal of such heating elements from thefurnace ismade much more rapid than in constructions known in prior art. This isan important advantage, since it reduces the heat losses of electricalfurnaces which consume a large amount of electrical energy, and whichoperate at very high temperatures.

Furthermore, in accordance with the described construction, the blockcarrying the heating element is situated within the opening serving as acharge opening for the insertion of the material to be treated. Thequick removal and insertion of said block makes it possible to fill thecontainer with the material to be treated within a comparatively shorttime.

In certain instances the heating element and the two blocks supportingthe same may be firmly connected with the container. In such instancesit is advisable instead of completely rotating the container to cause itto carry out an oscillating movement about its central axis.

What is claimed is:-

1. In combination, a rotatable container, a. heating rod within saidcontainer, said rod having a threaded end portion, means firmly engagingsaid threaded end portion to support one end of said rod within saidcontainer, said means extending through an opening formed in said container and constituting a closure for said opening, a terminal adaptedto be connected to a source of electrical energy and connected with saidmeans, horizontally movable means connected with the first-mentionedmeans for supporting the same, means connected with the second-mentionedmeans for adjusting the vertical position of the second-mentioned meansrelatively to said container, means freely supporting the other end ofsaid rod within said container, another terminal adapted to be connectedto the source of electrical energy and connected with thefourth-mentioned means, means rotatable along with said container andsupporting the fourthmentioned means, the fifth-mentioned means beingmovable relatively to the fourth-mentioned means, and resilient meanscarried by the fifthmentioned means and pressing the fourth-mentionedmeans against said other end of the heating rod.

2. In combination, a rotatable horizontally disposed container, 9.single heating rod within said container, a block extending through acentral opening formed in said container and constituting a closure forsaid opening, said rod having a threaded end portion which is screwedinto a threaded opening formed in said block, a terminal adapted to beconnected to a source of electrical energy, means electricallyconnecting said terminal with said block, horizontally movable meansconnected with the first-mentioned means for supporting said block,means connected with the second-mentioned means for adjusting thevertical position of the second-mentioned means relatively to saidcontainer, means freely supporting the other end of said rod within saidcontainer, another terminal adapted to be connected to the source ofelectrical energy and connected with the fourth-mentioned means, meansrotatable along with said container and supporting the fourth-mentionedmeans, the fifthmentioned means being movable relatively to thefourth-mentioned means, and resilient means carried by thefifth-mentioned means'and pressing the fourth-mentioned means againstsaidother end of the heating rod.

3. In combination, a rotatable horizontally disposed container, aheating rod within said container, said rod having a threaded endportion, means firmly engaging said threaded end portion to support oneend of said rod within said container, said means extending through 'anopening formed in said container and constituting a closure for saidopening, a terminal adapted to be connected to a source of electricalenergy and connected with said means, a carriage'supporting said means,means for adjusting the height of said carriage, means freely supportingthe other end of said rod within said container, another terminaladapted to be connected to the source of electrical energy and connectedwith the thirdmentioned means, means rotatable along with said containerand supporting the third-mentioned means, the fourth-mentioned meansbeing movable relatively to the third-mentioned means, and resilientmeans carried by the fourth-mentioned means and pressing thethirdmentioned means against said other end of the heating rod.

HENRI GEORGE. GASTON DELPECH.

